- A copied page opens only if every row decodes the way hydration does, at
  a payload version this build reads (lib/strategy/copied_page_check.dart).
  Test fixtures now hold real drawable payloads.
- A read takes a write grant when it starts, and its answer is kept only
  if that grant is still current: nothing read before a sign-out or an
  account switch is kept, for either account.
- While the editor draws a page from the copy, the sync chip says offline,
  with the copy's age, never Synced.
- Without a copy (web, share links), reads behave as before the copy
  existed.
- The background refresh resumes when a dropped socket reconnects.
- Library badges count a page as kept only in a format this build reads.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>